I heard you can somehow read check engine light codes through the radio? No scanning tool needed?

How is this done?

I heard you can somehow read check engine light codes through the radio? No scanning tool needed?

How is this done?

I've some bad news for you. Unlike many earlier Cadillacs, you can't read the codes without using a scan tool.

And, the only two tools capable of reading all the codes correctly are the official tools - either the hand held Tech-2 or there is a PC based solution but that has to have a current account to operate. (If anyone knows of an alternate tool that covers everything, do mention it).

I assume (though I haven't tried it) that the emissions codes (P0XXX) will read on a universal scan tool, because it is in effect a legal requirement for emissions codes to work in this manner.